The muscles that propel you forward when you run are some of the most powerful muscles in the body. The quadriceps in the front of the thigh are the strongest muscle group in the body. The hamstrings are the strongest muscle for their size. The gluteus maximus in the buttocks and calf muscles are also pretty powerful.
So why are a pair of little muscles in the hips so important?
The hip is a ball and socket joint. There are six different directions the hip can move: forward, backward, to the outside, to the inside, rotating outwards and rotating inwards. That’s a lot of movement. In order for the hip to function well during running, it has to move forwards and backwards freely, but it also needs to be stabilized from side to side and rotation needs to be minimized.
Enter the gluteus medius and gluteus minimus. These are two muscles that both abduct (move the leg away from the body) and externally rotate the hip. If you are sitting in a chair reading this, place your right ankle on your left knee. Now your right hip is both externally rotated and abducted.
When you are running, these hip abductor muscles stabilize your pelvis and keep your pelvis level. This is important because without a stable pelvis, it is hard to generate force with your legs. Instead of having a firm push-off with your foot, the push-off will push back on your pelvis and much of your energy will be wasted.
Much attention has been given to core strength, which is defined as central muscle control to improve the function of the arms and legs. Using this definition, these muscles are really an extension of the core.
These muscles are notoriously weak in the general population. If the muscles are weak, you might end up leaning forward when you run to use your quads to help you stabilize the pelvis. This is one of the teachings of the Pose/Chi running techniques and is probably one of the reasons that this running technique requires more energy and is less metabolically efficient than normal heel-strike methods.
How can you tell if these muscles are weak? Stand on a single leg and squat down halfway. If your knee crosses towards the middle of the body or if you have to bend forward at the waist, you have weakness of these smaller gluteus muscles.
Strengthening these muscles is easy, since you are not trying to build bulk but provide endurance. You don’t need special machines, you can use body weight exercises. Pelvic drops can be done while standing on a step. To strengthen the right side, stand with your right foot on a step and the left foot hanging down. Let the left half of the pelvis drop to the side and raise it back up.
More functional exercises can be done by doing a single leg squat and keeping the knee over the big toe. To make this harder, you can also stand on a piece of foam or a bosu ball.
A more dynamic exercise can be done by performing jumping lunges. These can be done on a level surface by taking a giant step forward onto a single leg while keeping the knee in control by preventing it from crossing the midline.
Hip pain from weakness of gluteus medius and guteus minimus muscles is common in runners. Dynamic strengthening of these muscles results in more stable, less injury prone, and more efficient running.
 Dallam GM, et al. Effect of a global alteration of running technique on kinematics and economy. J Sports Sci. 2005 Jul; 23(7): 757-64
Michael Ross, MD is a sports medicine physician who has been treating endurance athletes for over a decade. He has been a team physician for numerous professional cycling teams. He also runs the Rothman Institute Performance Lab, a medical and scientific exercise testing and training facility in Bryn Mawr, Pennsylvania. He has written two books on training and sports medicine for endurance athletes as well as multiple scientific papers. He has been an invited speaker at USA cycling and consulted for several bicycle companies to provide the optimum fit. He is an avid triathlete himself who has qualified for short course triathlon nationals several times. When he is not at work or spending time with his family he can be found on the trails and the roads around Philadelphia. www.rothmaninstitute.com/physicians/michael-j-ross-md